Flexible supports for mounting television screens and computer monitors were limited by the size and weight of cathode ray tube display screens. U.S. Pat. No. 5,108,063 to Koerber et al. is illustrative of the problems and the sometimes ungainly solutions. Flat panel monitors, with reduced weight and depth and greater screen size availed multiple opportunities to provide enhanced flexibility of movement with a reduced footprint. U.S. Pat. No. 6,015,120 to Sweere et al. illustrates one option for such displays.
Cable routing from a signal generator to the display must vary with the thickness and flexibility of the cable provided with the display system and thus the number of wires required and how they are threaded to the screen is rarely shown in advertising for display arms. Attempts to route cables internally within parallelogram arms and swivel turrets and the ends of the arms, as disclosed in U.S. Pat. Nos. 6,719,253 and 6,983,917 have largely been failures and products corresponding to those patents have been superseded. Thicker, less flexible cables are difficult to route through narrow passageways around gas springs and integral plug connectors must be removed during routing and reattached. As a result, sling-type devices are preferred which are suspended from the lower, inner channel arms used in typical parallelogram-type support arms.
Early channel guides had slots along the bottom face into which cables could be pushed so as to be partially concealed and a plastic tray was clamped or snapped under the cable using a pair of flanges at the sides of a concave tray to slide over the edges of the slots. Larger cables required larger trays until the tray, not the slot, became the cable path.